This invention relates to the field of telephone wire connector blocks and distribution systems, and specifically to a connector and a test device for testing wiring connected to the connector.
In a telephone network, a network cable from the central office is generally connected to a junction box, such as, for example, a building entrance protector (BEP) or network interface unit (NIU) located at the customer site, where the individual telephone lines are broken out line-by-line. The network cable, which consists of a plurality of tip-ring wire pairs that each represent a telephone line, is typically connected to a connector block containing an array of individual connectors that forms a part of the BEP. Such connectors may be, for example, mini-rocker toolless insulation displacement (IDC)-type connectors, such as, for example, those sold by A.C. Egerton, Ltd. Other connectors used for telephony wiring applications are described in U.S. Pat. No. 4,662,699 to Vachhani et al., dated May 5, 1987, and in U.S. Pat. No. 3,611,264 to Ellis, dated Oct. 5, 1971.
The customer telephone equipment is coupled through such an IDC connector to, for example, a central office telephone line. The connector generally has a top section that includes two wire insertion holes and a housing within which a pair of spaced-apart terminal strips are disposed. The wire insertion holes each accommodate one wire of a tip-ring wire pair. The top section pivots about a generally hinged fixed axis located on the side opposite the wire insertion holes and has a movable clasp for maintaining the top section in its closed position.
To open the top section, a user releases the clasp member and pivots the top section to its open position. When the top section is in its open position, the terminal strips do not intersect the wire insertion holes, but when the top section is in its closed position, the terminal strips intersect the wire insertion holes. Therefore, to establish an electrical and mechanical connection between the wires and the terminal strips, a user first opens the top section (i.e., pivots the top section to its open position), inserts the pair of wires, and then closes the top section. Upon closing the top section of the connector, the wires are brought into electrical and mechanical contact with the terminal strips. To remove the wires and/or break the electrical connection, the process is reversed.
To verify the integrity of a telephone line, the telephone line may be tested at the connector using a bridge clip, a test probe or other common test gear. The bridge clip includes a body, at least a first test prong and a second test prong connected to the body, and lead wires for connecting the first and second test prongs to a testing device, such as a voltmeter or telephone test set. Two test channels sized to accommodate a test prong of the bridge clip are formed in the housing of the connector and a portion of a respective one of the pair of terminal strips is disposed in each of the test channels. The test channels of prior art connectors generally have uniform dimensions. That is, the width and depth of the channel remain constant along the entire length of the channel. The test prongs or test leads of the bridge clip are spaced apart and constructed to be received within the channels.
Testing is typically performed by inserting the test prongs of a bridge clip into the test channels of the connector until each of the test prongs contacts an outside edge of a respective one of the pair of terminal strips housed within the housing to make an electrical connection. If a current flow is detected, or a dial tone is heard, depending on the test methodology, then a loop condition exists for that particular tip-ring wire pair, and the integrity of the line is verified. If no loop condition is found, either an electrical open or short exists in telephone line or a connection to or in the terminal block is defective.
Prior art test prongs typically consist of flexible metallic strips or test probes that are bent inwardly at one location so as to bias the free end of the test prong toward the terminal strip when the test probes are inserted into the test channels of the connector. One example of such a bridge clip is A. C. Egerton part no. RBC2210. After repeated use, however, one or both of the test prongs tend to lose its original shape through the repetitive flexing of the prongs during testing. As such, the electrical contact made between the test prongs and the terminal strip made when the test prong is inserted into the test channel becomes unreliable, in part, because the test prongs are permitted to move within the test channel.
Further, the prior art connector testing systems do not prevent the user from inadvertently overinserting the test prongs to a position where the prongs cause damage to the connector. When correctly inserted into the test channels of the prior art connector, the prior art bridge clip body is spaced apart from the top section of the connector. Therefore, the prior art mini-rocker connector testing systems provide no indicator or signal to the craftsperson when the test prongs of the bridge clip are properly positioned within test channels of the connector.
The present invention is directed at overcoming shortcomings in the prior art. A connector testing system in accordance with the present invention preferably includes a bridge clip having a body and a test probe or test lead connected to the body at a proximal end of the test lead, a connector having a top section and a housing, and an electrically conductive terminal strip disposed within the connector. The housing has a test channel that is sized and shaped to accept the test probe, and within which a portion of the terminal strip is disposed.
The top section of the connector includes a sloping region and a shoulder formed at the lower edge of the sloping region. The shoulder is sized and shaped to accept the second bend of the test probe when the test probe is inserted into the test channel. The housing includes a side wall, having an upper portion and a lower portion, that defines one side of the test channel. The side wall includes a guiding portion positioned below the shoulder for both guiding the test probe tip into contact with the terminal strip portion and preventing the test probe from being further inserted into the test channel at a location where the tip contacts the terminal strip.
In a preferred embodiment, the test probe is bent in three locations to form three bends. When the test probe is positioned to be inserted within the connector for testing, a first section of the test probe is connected at a proximal end of the test probe to the body of the bridge clip and is bent at a first bend to form a second section. The second section extends distally from the first bend toward the top section of the connector. The second section is bent at a second bend to create a third section, which is angled away from the top section of the connector, and extends distally from the second bend. The third section is bent at a third bend to create a fourth section, which is angled toward the top section of the connector, and extends distally from the third bend. The test probe tip forms part of the fourth section and therefore is angled toward the top section of the connector. In this case, the guiding portion of the side wall has a slope that is substantially parallel to the slope of the fourth section of the test probe.
To test an electrical connection of the connector, the craftsperson inserts the test probe into the test channel until the tip contacts the sloping region of the top section. The sloping portion guides the tip into the test channel of the connector until the outside surface of the fourth section or the third bend of the test probe contacts the side wall of the connector. At this point, the craftsperson continues to insert the bridge clip into the test channel which causes the test probe to slide down the inner surface of the side wall until the outside surface of the fourth section of the test probe contacts the guiding portion of the side wall. At this position, the second bend of the test probe contacts the sloping region of the top section and is positioned at the lower edge of the sloping region, just above the shoulder. Further pressure by the craftsperson causes the first section of the probe to flex to permit the second bend to slide by the lower edge of the sloping region until the second bend contacts or seats against the shoulder. At this position, the test probe is firmly seated within the test channel between the inner surface of the side wall and the shoulder of the top section, and the tip of the test probe contacts the outer edge of the terminal strip.
Preferably, the length of the test probe portion between the second and third bends is approximately equal to the distance from the stop surface of the side wall to the shoulder of the top section such that, when the test probe is in the fully inserted position, the test probe is securely seated within the test channel between the stop and the shoulder. In this way, the stop together with the shoulder of the top section prevent the test probe from being overinserted into the test channel and provide surfaces that bias the test probe tip against the terminal strip. As such, the craftsperson is not required to hold the test probe to ensure proper contact with the terminal strip when testing the electrical connection. Further, when the test probe is in its fully seated within the connector, the craftsperson perceives an audible click or tactile vibration, or both, which act as a signal that indicates to the craftsperson to stop inserting the test probe into the test channel, thereby protecting the interior connector components from damage due to overinsertion.
In a second embodiment, the test probe includes a tip and is bent in at least at two locations to form two bends. Accordingly, the test probe is divided into at least three separate sections: a first section, which is attached to the bridge clip at the body at a proximal end and bent at a first bend to form a second section extending from the first bend in a direction away from the top section of the connector. The second section is bent at a second bend to form a third section that includes a tip formed at the third section distal section and extends from the second bend in a direction toward the top section of the connector. The test probe includes an outer surface having a projection located proximate to the first bend. As is described below, when the test probe is in its fully inserted position within the test channel, the second section of the test probe is compressed within the test channel and the test probe is secured within the test channel by the abutment of the projection against the top portion and the second section against the inner surface of the side wall.
To use the second embodiment to test an electrical connection of the connector, the craftsperson inserts the test probe into the test channel until the tip contacts the sloping region of the top section. The sloping portion guides the tip into the test channel of the connector until the outside surface of the third section or the second bend of the test probe contacts the side wall of the connector. At this point, the craftsperson continues to insert the bridge clip into the test channel which causes the second bend of the test probe to slide down the inner surface of the side wall until the outside surface of the third section of the test probe contacts the guiding portion of the side wall. At this position, the projection of the test probe contacts the sloping region of the top section and is positioned at the lower edge of the sloping region, just above the shoulder. Further pressure by the craftsperson causes the first section of the probe to flex to permit the projection to slide by the lower edge of the sloping region until the projection contacts or seats within the shoulder. At this position, the test probe is firmly seated within the test channel between the inner surface of the side wall and the shoulder of the top section, and the tip of the test probe contacts the outer edge of the terminal strip.
In this way, the testing system provides a reliable way of preventing overinsertion of the test probe and provides structure that holds the test probe in contact with the terminal strip while providing a positive strain relief to maintain the test probe at that position to ensure continuous electrical contact with the terminal strip during testing procedures.
Other objects and features of the present invention will become apparent from the following detailed description, considered in conjunction with the accompanying drawing figures. It is to be understood, however, that the drawings, which are not to scale, are designed solely for the purpose of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims.